Does the field encoding affect the speed and size of the table?

Question

MySQL

In my DB all fields are utf8mb4 encoded. Does it make any practical sense for fixed-length CHAR(64) text fields that contain only latin characters and is a unique index to use the latin1 single-byte encoding? Will there be a profit in terms of performance or table size?

Answer 1

If we are talking about a large table, tens of millions of records, then such a kind of "micro-optimization" is needed.